I used to think (probably informed by a colonialist mindset) that the only real law was Western in origin and that customary/tribal/indigenous "law" was only law in a metaphorical sense and in practice was little more than an eclectic mix of community consensus and warlord fiat. This changed when I read the utterly fascinating article An introduction to the Ngarra law of Arnhem Land by George Pascoe Gaymarani. It presents an overview of the traditional law of the aboriginal Yolngu people of northern Australia, covering substantive law, procedural law, specific remedies, penalties for noncompliance with court orders, and even regulation of legal professionals. Like any good article, it left me with far more questions than answers. There is plenty here to ask a dozen or more specific, non-opinion-based questions on Ngarra law. The high level of detail in the article also supports a hypothesis that other tribal and/or indigenous societies around the world have legal systems of similar complexity.
An example of a question that actually occurred to me after reading the above article is:
Gaymarani defines Galka as the "death penalty by sorcery" but does not clarify what he means by "sorcery". Is Galka a literal death sentence/judicially appointed homicide where the convicted offender's life is terminated by duly appointed executioners, or is it more of a ritualistic form of civil and social death and declaration of outlawry? If it is literal, are there rules on what techniques or weapons must or may be used (e.g. knives, being thrown off a cliff, etc.)? If it is a civil death only, is there a citation to the ritual somewhere?
Are questions about tribal, indigenous, etc. law on-topic here on Law Stack Exchange?
One possible objection could be that most lands in which customary legal systems are in place have been conquered and/or colonized by other powers who have imposed their own legal systems as authoritative. This could be trivially bypassed, however, by prefacing each question with "Before their lands were conquered by [Colonial Power] and their laws replaced by Colonial laws, [Substantive Question?]".
In response to Jen, I am aware that there are probably not a large number of people on this site that could be described as experts in any system of customary law. Lack of specific experts, however, has never been a valid close reason anywhere on the Stack Exchange Network. Indeed, questions about obscure or obsolete programming languages are and have always been on-topic on Stack Overflow, and occasionally a question on one gets a good answer.